New Zealand Glacier Monitoring: End of summer snowline survey 2013

Transcription

1 New Zealand Glacier Monitoring: End of summer snowline survey 213 Prepared for New Zealand Ministry of Business, Innovation and Employment January 214 Photograph: Glenmary Glacier, Naumann Range, Lake Ohau catchment on 12 March 213 (A.Willsman)

2 Authors/Contributors: A. Willsman T. Chinn A. Lorrey For any information regarding this report please contact: Andrew Willsman Technician Field Team National Institute of Water & Atmospheric Research Ltd 1 Kyle Street Riccarton Christchurch 811 PO Box 862, Riccarton Christchurch 844 New Zealand Phone Fax NIWA Client Report No: CHC Report date: March 214 NIWA Project: CLCO142-1 Climate Present and Past All rights reserved. This publication may not be reproduced or copied in any form without the permission of the copyright owner(s). Such permission is only to be given in accordance with the terms of the client s contract with NIWA. This copyright extends to all forms of copying and any storage of material in any kind of information retrieval system. Whilst NIWA has used all reasonable endeavours to ensure that the information contained in this document is accurate, NIWA does not give any express or implied warranty as to the completeness of the information contained herein, or that it will be suitable for any purpose(s) other than those specifically contemplated during the Project or agreed by NIWA and the Client.

3 Contents Executive summary Introduction Glaciers and climate change The Equilibrium Line Altitude (ELA) Field methods The survey flights March 213 fieldwork details Derivation of the glacier snowline ELAs derived by digitising ELAs derived by interpolation ELAs derived by snow-patch size when the snowline is obscure Accuracy of values associated with ELA measurements Derivation of the Long-term or Steady-state ELAo value The 213 snowline results The 212/213 glacial climate Photographic coverage of the index glaciers Snowline elevation departures Glacier representivity Discussion Ice gain and loss Acknowledgements References Glossary Appendix A Index Glacier ELAs (-213) Appendix B Index Glacier details Tables Table 3-1: Derived AARo values for New Zealand glaciers. 16 New Zealand Glacier Monitoring: End of summer snowline survey 213

4 Table 4-1: Correlation coefficients of individual snowline departures for each glacier correlated against the mean of all remaining values for the period Table 5-1: Generalised climate for 212/213 year and previous 12 years in Southern Alps and inferred glacier snow input. 28 Table 5-2: Vertical gradients of mass balance as measured for Ivory and Tasman Glaciers (mm/m). 29 Figures Figure 1-1: Location of the 5 index glaciers across the South Island of New Zealand. 6 Figure 1-2: Basic parameters of a glacier. 8 Figure 2-1: Flight paths for 213 glacier snowline survey. 11 Figure 2-2: Geopotential height anomaly map at the 1hPa level for the flight on 12 March Figure 3-1: Schematic diagrams of stratigraphy at the glacier equilibrium line. 13 Figure 4-3: Southwest Pacific anomalies at the 1hPa geopotential height (top row) April-June 212 (left) and July-September 212 (right). 2 Figure 4-4: Southwest Pacific anomalies at the 1hPa geopotential height (top row) October-December 212 (left) and January-March 213 (right). 21 Figure 4-1: Histogram plot of the 212/213 snowline departures (raw and response normalised) for each index glacier from the long-term ELAo. 22 Figure 4-2: Mean annual departures (raw and normalised) from the ELAo for all measured glaciers for the entire period of the surveys. 23 Figure 5-1: Raw and Scaled Cumulative Mass Balance Indices for the index Glaciers. 26 Reviewed by Approved for release by Christian Zammit Charles Pearson New Zealand Glacier Monitoring: End of summer snowline survey 213

5 Executive summary Glaciers of New Zealand respond to the changing climate, and an integration of these changes over time are recorded by annual aerial surveys. These surveys measure the altitudes of the snowlines of 5 glaciers at the end of summer, as a surrogate for annual glacier mass-balance. The surveys have been made in most years since, but rarely do conditions permit all of the 5 index glaciers to be surveyed each year. The surveys are carried out by hand-held oblique photography taken from a light aircraft. Both the absolute and relative positions of the snowlines are recorded and this provides a time series of glacier-climate interaction back to. On average, the latest survey of index glaciers indicated a small positive mass balance for the 212/213 glacier year (March 212 to March 213), i.e., the snowlines, the equilibrium line altitudes (ELAs), were slightly below their average elevation. Winter snow on most of the index glaciers was covering approximately two-thirds of their respective areas. There was some variation in the index glaciers across the Southern Alps this year but this seemed due to variability in index glacier response rather than any geographical trend. Neutral ENSO conditions were present in the southwest Pacific across the glacial year. Anticyclones ( highs ) dominated at the start of the season, with intense ridges of high pressure east of the Chatham Islands extending back over the South Island persisting in the late season. Late spring and early summer were characterized by more Southwesterly winds. Two to three months early in the glacier year had below normal precipitation, and many sunshine hours and high temperature records were broken near the end of the year. Regional sea surface temperatures were near or above normal at the start and end of the year, and near normal at other times. Based on the climate summary information, the input from snowfall was estimated as average to low for this season. The small positive mass balance this year is a change from the large negative mass balance conditions the previous two years (21/211, and 211/212). A neutral mass balance year occurred in 29/21. Prior to this there had been two further years of strong negative mass balance (27/28, 28/29). The glaciers have shown a varying pattern of positive (23 years) and negative (14 years) mass balance over the 37 year monitoring period. However, many of the index glaciers with well-defined permanent ice areas have clearly lost ice during the course of the 37 year monitoring period. This mass loss has occurred during large negative mass balance years and has not been replaced during the positive mass balance years. New Zealand Glacier Monitoring: End of summer snowline survey 213 5

6 1 Introduction The results presented in this report continue an annual glacier/climate photographic monitoring programme, begun in, of the position (altitude) of the end-of-summer snowline on 5 selected index glaciers, arranged in several transects across the Southern Alps (see Figure 1-1). Figure 1-1: Location of the 5 index glaciers across the South Island of New Zealand. Between and 1985, a New Zealand glacier inventory was undertaken from Mount Ruapehu in the North Island at 39 15' S to southern Fiordland at S. A total of 3144 glaciers were identified for the inventory, where a glacier was defined as a permanent area of snow greater than.1 km 2 (one hectare). In the South Island, average peak summits range from 185 m in Fiordland to 3 m in the central Southern Alps and descend to 2 m in the north-central Southern Alps. To the north east, the Kaikoura ranges reach to over 27 New Zealand Glacier Monitoring: End of summer snowline survey 213 6

7 m, where active rock glaciers have developed under the relatively dry climate. Three North Island volcanic cones reach close to the permanent snowline, but only Mount Ruapehu, with a summit at 2752 m, supports glaciers. Logistics of the glacier over flights do not currently allow the North Island region to be included in annual surveys because of the distances involved. New Zealand has a humid maritime climate, with the Southern Alps lying across the path of the prevailing westerly winds. Mean annual precipitation rises rapidly from 3 mm along the narrow western coastal plains to a maximum of 15, mm or more in the western part of the Alps close to the Main Divide. From this maximum, precipitation diminishes to about 1 mm in the eastern ranges over less than 3 km from the divide. This creates a steep westeast precipitation gradient across the Southern Alps, and the mean altitude of the glaciers closely follows this gradient (Chinn and Whitehouse 198). 1.1 Glaciers and climate change Glacier fluctuations are amongst the clearest signals of climate change, because glaciers are highly sensitive indicators of the earth s surface energy balance. Glaciers register distinct signals of past climate change on scales from decades to millennia. Atmospheric changes are signalled by direct, immediate changes in annual mass balance, which are filtered, and smoothed before they become apparent at the glacier front. Glacier snowline altitudes provide a direct value for annual glacier health and balance. Changes indicated by glacier frontal positions are strongly modulated by glacier response times and dynamics related to climate variability, so determination of annual glacier change using frontal positions is problematic. 1.2 The Equilibrium Line Altitude (ELA) The winter snowpack normally covers the entire glacier in a wedge shape, with the greatest snow depths near the highest altitudes, tapering to zero at the lower edge (Figure 1-2). This lower margin, or transient snowline, of the snowpack retreats up-glacier as summer melt progresses, until it reaches a maximum altitude for the year at the end of summer (March - April). Located somewhere near the mid-point of the glacier, the end-of-summer snowline indicates where snowfall exactly equals snow loss over the past glacial year (Figure 1-2). This line of demarcation is termed the equilibrium line, which is normally visible as a contrast on the glacier surface between discoloured dust on firn (below the equilibrium line) and the clean snow of the previous winter (above the equilibrium line). It is the altitude of this glacial feature that is defined as the Equilibrium Line Altitude (ELA) by Meier and Post (1962). The ELA is measured each year by the snowline survey. The higher the altitude of the ELA, the less the amount of snow remaining to nourish the glacier after summer melt, indicating a lower mass balance. Conversely, a low annual ELA indicates a large amount of residual snow remaining at the end of summer and a positive mass balance. It follows that there is a unique position for the ELA across the glacier where the volume of snow accumulated over the past year exactly balances the total volume of snow and ice lost during the year. If the ELA were to lie at (or maintain an average of) this altitude for many years, then there would be no change to the mass or size of the glacier (assuming no other processes are involved, e.g., ice-margin lake development and calving). This unique position of the snowline, which indicates that the glacier is in equilibrium with the climate, is defined as the steady-state Equilibrium Line Altitude (ELAo). A snowline of this altitude will indicate zero change to the New Zealand Glacier Monitoring: End of summer snowline survey 213 7

8 balance of the glacier. To avoid confusion between the annual and the long-term ELAs, some authors have also referred to the altitude of the annual glacier snowline as the end-ofsummer snowline or EOSS. Figure 1-2: Basic parameters of a glacier. A shift in climate can change the glacier mass balance and alter the altitude of the annual ELA. Thus the annual snowline position with respect to the long-term average or steady-state ELAo (see section 3) is used as a surrogate for annual balance changes at each glacier (Chinn, 25; Chinn, 1995). It is the departure of the glacier snowline from the steady-state ELAo, ie., ELAo - ELA that is reported here. These ELA departure values provide a measure of mass balance changes. Glacier studies worldwide (e.g., Haeberli et al., 27) have demonstrated that, on average, the accumulation area is about twice that of the ablation area so that the ELAo lies at an altitude where the ratio of the accumulation area (AAR) to the total glacier area has an average value close to.66. For this programme, the steady-state ELAo was initially estimated using AAR values of.66 for each glacier, then, as more ELA data were obtained, these approximate values have been progressively adjusted for most index glaciers as outlined in Section 3 below. 8 New Zealand Glacier Monitoring: End of summer snowline survey 213

9 2 Field methods Collection of field data involves flying over the glaciers in a light aircraft to take oblique photographs of the position of the end-of-summer glacier snowlines. A GPS with waypoints has been used since 27 and this has ensured that the oblique photographs have been taken from a similar position every time. It is worth noting here that the GPS waypoints are not of the glacier snow line itself, but the position in the air above the glacier, to achieve the same oblique photo. The snowlines visible on the photographs have historically been sketched on to a map of each glacier and the resulting accumulation or ablation areas are mapped and measured by digitisation. Since 28 the area interpretation has been done for selected glaciers by digitally rectifying the oblique photos then mapping the accumulation or ablation areas. The snowline altitude can then be accurately assessed from the glacier area-altitude curve or directly from a digital elevation model. 2.1 The survey flights On the flights, the navigator seated beside the pilot, holds a folder of photographs of each glacier. These photographs are used to closely duplicate the position from where previous photographs were taken. Photographs are taken by small- and medium-format SLR cameras, and since the 21 flight, by digital SLR cameras. Data on selected glacier termini, geomorphic features, such as moraines and supra-glacial lakes, are recorded in addition to the index glacier end of summer snowlines. The flights are generally flown between 9, ft (2,7 m) and 1, ft. (3, m). The upper limit is determined by civil aviation regulations. Significant snow melt continues throughout February and March, but by April there is a high probability that the first winter snowfall in the Southern Alps will have occurred. Experience has shown that although successful surveys have been made in April, there is about a 1 in 4 probability of a snowfall before this time. Every year the challenge of the survey is to measure the highest altitude reached by the rise of the glacier snowline as ablation losses precede, before the first winter snowfall. A light fall of fresh snow will conceal the position of the snowline as effectively as a coat of paint. The problem has been standardised by setting the earliest date for the flight at March 1. A successful survey cannot be guaranteed as there is also a 1 in 1 probability that there will be no suitable flying weather in the month of March before a fresh snowfall occurs because of the prevailing westerly circulation. As well, suitable weather to fly the entire Southern Alps demands particularly settled cloud free conditions. 2.2 March 213 fieldwork details A decision was made before the fieldwork commenced to do a one day flight over the central section of the Alps during early March. This region from north of Wanaka to Arthurs Pass contains 36 of the 5 index glaciers, and it is possible to fly this in one day. Then if melt conditions continued into late March and April an extended two day survey of all 5 index glaciers would be conducted to capture this late season melt. On Tuesday 12 March the first leg of the one day survey flight departed Queenstown in a Milford Sound Flights Cessna 26 piloted by Andy Woods, with Trevor Chinn, Andrew Willsman (NIWA Dunedin), and Heather Purdie (University of Canterbury). This flight headed New Zealand Glacier Monitoring: End of summer snowline survey 213 9

10 north to the Thurneyson Glacier and continued up the eastern side of the Alps to the Arthurs Pass glaciers. Conditions were very good for photographing the glaciers with clear skies and obvious clear snowlines present on all the glaciers. Thick low cloud covered the Canterbury plains, inland basins and many of the valleys, but this cloud was well below the elevation of the glaciers. After photographing the Arthurs Pass glaciers we diverted to Hokitika for lunch and a fuel stop. The return trip to Wanaka was down the western side of the Alps. Fine weather afternoon cumulus cloud thickened south of Mt Whitcombe, and this either partially or completely obscured some of the index glaciers. The index glaciers on this western side had obvious clear snowlines at relatively low elevations on their respective areas. After photographing the glaciers on the Haast Pass transect we continued southwest to the index glaciers on the Arawhata to Matukituki transect. The Findlay glacier was completely covered in thick cloud but the remaining glaciers to the east were clear of the cloud. Leg 2 of the survey finished at Wanaka and Trevor and Heather departed here. Andy Woods was then asked by Milford Sound Flights to pick up passengers from Milford Sound and bring them back to Queenstown. He offered to taken Andrew along to photograph any index glaciers that were on the route from Wanaka, Milford to Queenstown route. Good photographs were taken of Park Pass, Llawrenny Peaks, Genderme, Ailsa and Bryant Glaciers on this leg. The four index glaciers in southern Fiordland were not visited. Photographs were taken of 41 of the 5 index glaciers on this one day flight. The second flight planned for late-march or April did not happen due to indifferent disturbed weather over the month bringing light dustings of new snow across the Alps. We did not get the combination of another settled cloud-free weather window, and snowlines on the glaciers that were not obscured by new snow. A photograph of the index glacier on Mt Larkins was collected on the 18 April during a visit to the plateau immediately below the glacier to install the foundations for a new climate station. The snowline was still visible in this photograph although a day after this visit a snowfall obscured snowlines on this glacier and on many others across the Alps. Figure 2-1 presents an overview of the glacier flight path for 213. The weather situations for the two flights are shown in Figure New Zealand Glacier Monitoring: End of summer snowline survey 213

11 Figure 2-1: Flight paths for 213 glacier snowline survey. New Zealand Glacier Monitoring: End of summer snowline survey

12 Figure 2-2: Geopotential height anomaly map at the 1hPa level for the flight on 12 March 213. Courtesy of NCEP/NCAR reanalysis. Anomalies are relative to the average conditions. 12 New Zealand Glacier Monitoring: End of summer snowline survey 213

13 3 Derivation of the glacier snowline Data in this report are presented as departures from the ELAo which represents departure of the climate of the year from the mean climate for glacier equilibrium. Thus an accurate estimate of the position of the ELAo is an important part of the programme. Associated glacier parameters used are accumulation area (Ac of Figure 3-1) and ablation area (Ab of Figure 3-1); total glacier area A, or Ab +Ac; and accumulation area ratio (AAR) the ratio of the accumulation area to the entire area of the glacier, Ac/(Ac+Ab). Figure 3-1: Schematic diagrams of stratigraphy at the glacier equilibrium line. (A) for a year of negative balance (high ELA) and (B) for a year of positive balance (low ELA). Numbers indicate age in years of past firm layers. At the commencement of this project, the value of the ELA was gained by plotting the observed snowline directly on to a topographic map:- Map + snowline ELA On the average glacier, the long term EOSS (ELAo) divides the accumulation and ablation areas by an approximate ratio of 2:1 (AAR value of.66). This position was estimated on small glaciers, and derived from the area-altitude curve on the larger glaciers. As the number of years of data increased, many of the ELAo values were subjectively adjusted (see section 3.5 for details of the adjustment methods):- Est. ELAo, + adjustment refined ELAo. Leading to small annual changes to:- ELA ELAo Departure value The use of a GIS mapping system associated with digitised areas has added significant accuracy to the data by supplying measured glacier and accumulation or ablation areas:- New Zealand Glacier Monitoring: End of summer snowline survey

14 Digitised (Ac or Ab) + Area Curve Digitised Ac + Glacier Area accurate ELA accurate AAR In addition, with a longer time series of annual photographs it is frequently more efficient to directly interpolate ELA values between those of previous years which bracket the current year s snowline (described below), and more than half of the ELA values have been derived by this method:- Interpolation Where ELA ELAo and ELA + Area Curve direct ELA Departure AAR The most significant problems in processing the results are recognising the position of the true end-of-summer snowline (Figure 3-1), especially when; There has been a recent summer snowfall, which effectively paints out the snowline. The snowline has been only partially recorded due to cloud cover, backlighting or other reasons. The current snowline is obscure or ambiguous due to limited discolouration of snowpacks of previous years. There is a wavy or patchy snowline. Glacier snowline elevations are normally obtained from detailed mass balance studies where the snowline is mapped as the zero isohyet on the annual mass balance map. Results from glaciers around the world where this technique is used are published in the Glacier Mass Bulletin (WGMS, 211). In this study the snowlines are derived from oblique aerial photographs by one of three methods, depending on the snow cover conditions at the end of summer: 1. Digitalisation method: Digitising either the accumulation or ablation area to provide a definitive ELA; 2. Interpolation method: Interpolating between photographs of past years where a number of snowlines are close in altitude; 3. Snow patch method: Comparing the sizes of adjacent snow patches when fresh snow or cloud obscures the snowline of the index glacier. These procedures are given in Chinn (1995) and in Chinn and Salinger (1999). 3.1 ELAs derived by digitising This method gives the definitive ELA values upon which the interpolation and snow patch methods rely. Here the end-of-summer snowline positions are carefully sketched from the oblique photographs onto detailed base maps of each glacier. The mapped accumulation or ablation 14 New Zealand Glacier Monitoring: End of summer snowline survey 213

15 zones are then digitised using GIS techniques to accurately measure the areas. From 29 on, however, some of the oblique digital images are now rectified using the Photogeoref software (Corripio, 24). This software utilised the camera position (GPS input), focal length, image size, NZ Digital Elevation Model, and ground control points (clearly observed features identifiable on the NZMG topographic map sheets) to rectify the image. From the total ablation area for each glacier, the snowline elevation is then read off an areaaltitude curve constructed for each glacier. Once the accumulation area is measured, the ablation area is found by subtracting the accumulation area from the total glacier area. This method provides a single figure for the glacier ELA for the year, regardless of the shape of the measured area, as it eliminates subjective estimation of the altitude of the snowline. The difference between this altitude and that of the long-term ELA indicates the annual mass balance of the glacier. Positive values or high snowline elevation signifies less snow and therefore a negative balance. 3.2 ELAs derived by interpolation With the many photos now available, for many glaciers it may be more accurate and efficient to obtain the ELA value by interpolation. For each glacier, photos for all years are arranged in increasing area of snow cover (descending order of ELAs). The current year s photograph is then carefully compared and inserted into its appropriate place in the sequence. It has been found that very small differences in snow cover can easily be recognised and that two photos separated by many years can have identical snow coverage. The ELA value is interpolated from the ELA values of the adjacent years. Depending on the similarity of the ELAs, this method frequently places the value of the ELA within a few metres. 3.3 ELAs derived by snow-patch size when the snowline is obscure Where the true end-of-summer snowlines are obscured by fresh snow, cloud or other reasons, the hidden snowline may be interpolated from the degree of snow cover surrounding the glacier, i.e., the size of the intermittent snow patches. Fresh snow on rock has quite a different appearance from fresh snow on existing snow, and it is commonly possible to discern the snow-patch outline beneath a light cover of new snow. As in the interpolation method, photographs of the glacier for all years are arranged in order of increasing snow cover on the glacier, which is also the sequence of the size of the snowpatches surrounding the glacier. The photograph from the latest survey is then slotted into its appropriate place in the snow-patch sequence. The ELA values for this glacier are interpolated from those of adjacent years as described above. This subjective assessment has proved to be surprisingly consistent (see Chinn et al, 22). 3.4 Accuracy of values associated with ELA measurements Accuracy of the data is dependent on the accuracy of the digitised Ac and/or Ab areas, glacier area and its area curve. Normally all of these values are measured with a high degree New Zealand Glacier Monitoring: End of summer snowline survey

16 of accuracy provided the glacier maintains a constant size. However many of the smaller glacier have undergone large variations of size and both the area and associated areaaltitude should be re-measured each year of change. Associated with small glaciers and area changes are the problems of when the snowline (ELA) rises above the glacier or falls below the glacier terminus. When the ELA falls below the glacier, the ELA can be estimated, but the AAR becomes >1 which causes mathematical problems. When the ELA rises above the glacier, it is not possible to extrapolate its value and the AAR becomes negative. 3.5 Derivation of the Long-term or Steady-state ELAo value Glacier studies worldwide have demonstrated that the ELAo lies at an altitude which divides the accumulation area from the ablation area in a ratio of near 2:1, and this ratio has been used extensively for the derivation of paleo-snowline altitudes (Maisch, ). The accumulation area ratio (AAR) of accumulation area to the total glacier area has an average value close to.6 (Paterson, 1994). However, accumulation ratios can range from about.25 to.75 (Haeberli, Hoelzle, and Zemp, 27) with the largest deviations occurring for abnormally shaped glaciers (Table 3-1). The 2:1 ratio of the accumulation to ablation areas, or AARo of.66, was tested and found to apply to New Zealand glaciers without debris cover, terminal lake or an abnormal shape. The test uses the snowline data from the index glaciers as determined from 29 years of monitoring given in Hoelzle, et al. (27). Values of AARo for each index glacier in Appendix B are estimated from the accumulation and ablation areas on the area elevation curve at the ELAo elevation. They vary considerably with the type of glacier, from.9 to.84. Closer examination shows that the largest deviations are for glaciers with extensive debris cover, and for those with pro-glacial lakes. The results of Table 3-1 show what happens to the mean AARo for the index glaciers as the classification is changed. The nearer the selection to the morphology of a normal glacier, the closer the accumulation area ratio approaches the.66 mean. Initial observations of the index glacier AAR values suggest that the most significant of the topographic controls for raising the AAR value (lowering the ELA) appear to be the surface gradients below the ELA and any divergence of ice flow. Conversely any flattening of the glacier tongue lifts the ELA to drive a low AAR value. Surprisingly, parallel flow as is common in ice aprons, does not appear to affect the AAR. Table 3-1: Derived AARo values for New Zealand glaciers. Sample Number Mean AARo Std Dev All index glaciers Without (a) rock glaciers Without (a) and (b) lakes Without, (a),(b), and (c) abnormal shapes Mass balance, the specific depths of mass gain or loss over a balance year, do not follow an even change along the glacier profile, and for simplification, mid-latitude glaciers are usually assumed to have a single linear gradient along the longitudinal profile of the glacier. 16 New Zealand Glacier Monitoring: End of summer snowline survey 213

17 However, for equilibrium, the volume of snow gained during the glacier year equals the volume of the ice lost (using water equivalents). Due to the 2:1 rule used here, the accumulation area is approximately twice the ablation area. Thus for the purposes of this work, it is assumed that the ablation mass balance gradient is twice the accumulation gradient Values for the long-term ELAo were initially derived by applying an AAR value of.66 (Gross, et al. 1976) to the area-altitude curve for each glacier. The ELAo is read off the glacier area curves at.4 of the area up from the glacier terminus. Initially the ELAo values were approximate estimates only, as measured AARs on glaciers in equilibrium vary from.5 to.75, depending on glacier topography and other factors. The ELAo may then be adjusted using the record of annual ELAs and the annual mean ELA for all index glaciers. The method assumes that the ELAo indicates the snowline position for a zero mass balance, and that ELA changes each year on an individual glacier are linearly proportional to the average change over the entire Southern Alps. The regression plots for each of the index glaciers are given in Appendix B, where the annual departures for each glacier are regressed against the annual mean for the Alps without the glacier in question. The correlation and representativeness indicated by these regressions is discussed below. At the zero intercept, which indicates a zero average mass balance for the Alps, the mass balance of the individual glacier should also be zero. The adjustment of the ELAo from its estimated value to a precise value indicated by the dataset is carried out using the constant of the regression equation. The slope of the regression line indicates the character of the response of the glacier to the climate, within the constraints of the assumptions of linearity. The average climate response is given by the mean for the Southern Alps, so that any deviation from a 45 o slope is an indicator of the individual characteristics of the glacier. Since each year s climate is thought to be similar over all of the Southern Alps, with the noted exception of the Kaikoura Ranges, which lies in a distinctly different climate district (Mullan, 1998; Mullan and Thompson, 26)), the regression slope changes must represent a topographic signal in the ELA values. Similarly, the range of the highest and lowest ELA values is also influenced by the glacier topography. The significance of these properties has yet to be analysed and warrants further investigation. New Zealand Glacier Monitoring: End of summer snowline survey

18 4 The 213 snowline results 4.1 The 212/213 glacial climate A summary of key regional and local climate conditions taken from the National Climate Centre s monthly summaries from April 212-March 213 is found below, broken down by season within the glacier mass balance year (April-March). Overall, the atmospheric circulation pattern was typified by more frequent anticyclones ( highs ) in the early and late season, with more southwesterlies during late spring and early summer. April-June 212 MSLP during the early part of the glacial year changed from highs over the South Island in April in mid-autumn to an increased frequency of low pressures at the onset of winter. Overall, this three-month period had subtly higher pressures than normal over northern and western regions Winds changed from relatively calm conditions that accompanied highs to more southwesterly flow by the end of the season Precipitation was below normal for the first two months of the season and near normal for the Southern Alps in June Air temperatures were mostly above normal at the start of the season and transitioned to very cool (below normal) for alpine regions of the South Island. Regional SSTs were near normal or above normal surrounding the South Island and above normal in the central Tasman Sea Snowfall occurred at the end of April, one notable event in May, and significant events in the central and southern South Island happened on 5-6 June and June July-September 212 MSLP for July and September saw lows over the north and central Tasman Sea and highs to the SE of New Zealand. For the three month period, anticyclones over the Chatham Island and east of the South Island were very pronounced Winds were mostly from the northerly quarter for this season, and predominantly from the northeast for July and August Precipitation was mostly normal or above normal during this time Temperatures were above average for most of the three-month period, with near-record mean maximum air temperatures at Milford Sound and Mt. Cook in July and record or near-record mean air temperatures in central and southern South Island locations. SSTs were near normal around most of the South Island and in the central Tasman Sea 18 New Zealand Glacier Monitoring: End of summer snowline survey 213

19 Several snowfall events occurred in August, and warm conditions generated snowmelt-induced avalanches in early September October-December 212 Near-surface pressures were much lower than normal southeast of New Zealand, and slightly higher than normal in the west-central Tasman Sea for the three month period The regional atmospheric circulation pattern produced more southerly and southwesterlies for a majority of the time, with a change to northerly and NW winds in December Precipitation was changeable from October-December, with very wet conditions recorded in the central Southern Alps in October (with record rainfall in Hokitika), while normal or below normal rainfall occurred in November and December Temperatures were below normal for October and November in southern and western regions, returning to near normal by the end of the year. Regional sea surface temperatures were near normal around most of the South Island. Significant snowfall events were restricted to October January-March 213 The end of the glacial year was characterized by highs that continued to build from late January and largely persisted through March. The regional atmospheric circulation pattern saw strong and persistent highs over the Chatham Islands and east of NZ which stretched back over the country and into the Tasman Sea. Winds were mostly settled in the mid-to-late part of this season Precipitation was well above normal in the beginning of January due to a couple of weeks of disturbed NW flow, producing the highest monthly total for Milford Sound (118mm) since records began in This was followed by the driest February on record at the same site, and two months in a row with record or near-record high sunshine hours Temperatures were below normal in Westland and Fiordland in January, but followed by above average temperatures in February and near-record mean maximum air temperatures across the South Island. Near-to-above normal SSTs surrounded the South Island during January-March One late snowfall event was recorded as low as the Lindis Pass in January New Zealand Glacier Monitoring: End of summer snowline survey

20 Figure 4-1: Southwest Pacific anomalies at the 1hPa geopotential height (top row) April- June 212 (left) and July-September 212 (right). Geopotential indicates areas of relatively high or low pressure (green/red shades indicating highs, blue/purple shades indicating lows ). The bottom row shows the corresponding sea surface temperature (SST) anomalies across the New Zealand sector for the same time period (green/red shades indicating warmth, blue/purple shades indicating cool). 2 New Zealand Glacier Monitoring: End of summer snowline survey 213

21 Figure 4-2: Southwest Pacific anomalies at the 1hPa geopotential height (top row) October- December 212 (left) and January-March 213 (right). See Figure 4-3 for details about contours. 4.2 Photographic coverage of the index glaciers Forty two of the fifty index glaciers were photographed this year. All but one of these were photographed during the survey flight, an additional photograph of the glacier on Mt Larkins was taken in mid-april on visit to a climate station at the base of the glacier. Thirty one glaciers were photographed from their standard waypoints, the remaining are taken exceptions were in the best location available to avoid cloud on or around the glaciers. The glaciers north of Lewis Pass and in Fiordland south of Lake Te Anau were not visited. A low resolution image of each index glacier photograph is in Appendix B. The photographs were taken with a Nikon D2 digital camera (sensor size = 23.6 x 15.8 mm, 3872 pixels x 2592 pixels, effective pixels = 1 megapixels) linked to a Garmin GPSmap 6Csx with an external aerial on the windscreen of the plane. Each digital image has the GPS location (latitude and longitude WGS84 datum) and focal length embedded in the EXIF information part of the digital photograph. The GPS used on the survey was set to the NZMG projection system and was displaying these values on screen, but was outputting WGS84 latitudes and longitudes through the serial interface to the digital camera. These photographs are available as compressed jpegs from the digital archive. All the glaciers had obvious snowlines at relatively low elevations on their respective areas. New Zealand Glacier Monitoring: End of summer snowline survey

22 4.3 Snowline elevation departures Monitoring results for the 42 index glaciers for the 212/213 glacial year, together with the means for all measured years from to 213 are shown in Figure 4-1 and 4-2 respectively. Annual data for all measured glacier ELA departures from the long-term ELAo from to 213 are given in the matrix of Appendix A and are presented in Figure Departure from ELAo (m) KAIKOURA RA MT. ELLA MT FAERIE QUEENE MT. WILSON MT. FRANKLIN ROLLESTON GL. MT. CARRINGTON MT. AVOCA MARMADUKE GL. RETREAT GL BROWNING RA DOUGLAS GL MT. BUTLER DAINTY GL KEA GL JASPUR GL SIEGE GL VERTEBRAE #12 VERTEBRAE #25 RIDGE GL. LANGDALE GL. TASMAN GL. SALISBURY GL JALF GL CHANCELLOR DOME GLENMARY GL. BLAIR GL. MT McKENZIE JACKSON GL. JACK GL. MT. ST. MARY THURNEYSON GL BREWSTER GL. MT. STUART LINDSAY GL FOG PK SNOWY CK MT. CARIA FINDLAY GL. PARK PASS GL. MT. LARKINS BRYANT GL. AILSA MTS. MT. GUNN MT. GENDARME LLAWRENNY PKS. BARRIER PK. MT. IRENE MERRIE RA. CAROLINE PK. Index Glacier Raw departure Response normalised departure Figure 4-3: Histogram plot of the 212/213 snowline departures (raw and response normalised) for each index glacier from the long-term ELAo. Thirty individual index glaciers for 212/213 have raw and normalised ELA departures that are below the long-term mean ELAo position (Figure 4-1), of these 27 are in the range between and 1m below the ELAo position. The 3 outliers greater than 1m below the ELAo position did appear to have snowlines very low on their respective areas. Twelve glaciers have ELA departures above the long-term mean ELAo position, and of these 1 are within 5m of the mean position. Two individual index glaciers have departures greater than 5m above the long-term mean ELAo position. Of these Langdale Glacier has been problematic over the years as area changes and wind distribution of snow have effected snowline elevations. Mt Larkins has a large departure above the mean position, and this is possibly a combination of the large vertical patchy distribution of its glacier area making it difficult to determine the snowline elevation and the long term mean ELAo position, and it may also reflect that this photograph taken on the 18 April a month later than the remaining glaciers. The individual departure response of each index glacier varies due to topographic factors (discussed in section 3.5) and this variation can be normalised to consistent values by 22 New Zealand Glacier Monitoring: End of summer snowline survey 213

23 applying the slope from the regression between the annual departure and the annual mean alps value (regression slope values in Appendix 2). The derived slope values are considered to be reasonably valid as there are now a considerable number of observations, with 4 index glaciers having 27 or more annual observations and the least number of annual observations is 18. Figure 4-1 presents the raw and normalised departure values from ELAo for the index glaciers over the 212/213 glacial year. The effect of normalising is minimal as most of the index glaciers which have a near 1:1 ratio response to the Alps mean. Normalising does have the effect of reducing the magnitude of the offset for some of the glaciers with a large range of ELA values. It is assumed that the most inconsistent ranges in ELA values were those for snow-patch glaciers which do not have the conventional glacier elevation range, nor an ELA position. Up until now these values have been assigned as theoretical values and application of normalising has brought these difficult sites into line with normal glaciers. For example the 213 departures for Mt Larkins and the Douglas Glacier are almost halved after the topographic normalising is applied. This normalising for each glacier is especially important when aggregating the results for the full length of record for the whole of Southern Alps, as it accounts for the irregular sample size and the impact of individual glaciers with high sensitivities. Some variability exists between index glaciers after normalisation of departures and this is possibly due to a combination of geographical variability and measurement uncertainty. Mean Annual Departures (raw and normalised) Number of index glaciers sampled in each year Departure from ELA (m) Year Raw mean annual departure from ELAo Normalised mean annual departure from ELAo Figure 4-4: Mean annual departures (raw and normalised) from the ELAo for all measured glaciers for the entire period of the surveys. The raw mean snowline departure for this year (212/213), that is the average of all 42 ELA index glacier departures, was 26 m below the long-term mean ELAo position (Figure 4-2). New Zealand Glacier Monitoring: End of summer snowline survey

24 The average of the normalised 212/213 observations was 24 m below the long-term mean ELAo position. The 212/213 raw departure of 26 m below the long term mean ELAo position, indicates snowlines relatively low on the glaciers with a reasonable amount of winter snowpack remaining on the index glaciers. This equates to a small gain of snow and ice to the glaciers. Snowline departures have tended to be above or around the ELAo position for the 7 years (26 to 212) prior to this year indicating loss of snow and ice and negative mass balance. This loss of snow and ice is apparent at many of the index glaciers as loss of permanent ice area and fragmentation of previously continuous ice into smaller discrete areas. This reduction is particularly noticeable at some of the smaller index glaciers. The mean annual departures are presented in Figure 4-2 as raw and normalised amounts, and interestingly the results are similar as the effect of the outliers is relatively small when nearly all glaciers are sampled. The largest change due to normalisation occurred during / where the mean annual departure is reduced by 22 m from -125 m to -13 m, due to a small sample size of 15 index glaciers that contained some strongly sensitive glaciers. Full data records for each individual index glacier are given in Appendix 2. Missing values are years of no data for the particular glacier. Appendix 2 gives a data table, map and histograms of all measured snowline fluctuation histories as metres of departure from the steady-state ELAo for each index glacier. On the annual departure plots, missing values are years of no survey. The data table provides essential glacier data, snowline data statistics and a table of all measurements and immediate derived values. Photographs of each glacier are available from the digital archive and are included in low resolution in Appendix Glacier representivity The representativeness of each glacier as an indicator of the overall annual climate of the Southern Alps is indicated by how well the annual values for an individual glacier correlates with the mean value of the 5 index glaciers over the Southern Alps. Correlation coefficients of individual snowline departures for each glacier correlated against the mean of all remaining values for each year are given in Table 4-1. The correlation plots for each glacier are given in Appendix B. The correlations give a surprising result where representativeness appears to be independent of size, gradient or topography. The high correlations coefficient values indicate that the ELA surface of individual glaciers have a strong relationship with the mean ELA over the whole alpine range. This follows the finding of Clare et al. (24) where it was demonstrated that the entire Southern Alps behaves as a single climatic unit. However the consistently low correlation of the Kaikoura Range glacier suggests that the behaviour of this range is that of a separate climate zone, while it is assumed that accumulation on the low correlation Langdale glacier is dominated by wind redistribution. The low correlation of Faerie Queen, Snowy and Retreat are assumed to be due to difficulties in mapping these small area low elevation range glaciers. 24 New Zealand Glacier Monitoring: End of summer snowline survey 213

25 Table 4-1: Correlation coefficients of individual snowline departures for each glacier correlated against the mean of all remaining values for the period GLACIER Correlation Coefficient BARRIER PK..93 JALF GL.92 FINDLAY GL..91 VERTEBRAE #25.91 SIEGE GL.9 THURNEYSON GL.9 MT. BUTLER.89 MT. STUART.89 BRYANT GL..89 JACKSON GL..89 MT. ST. MARY.88 SALISBURY GL.88 LINDSAY GL.87 MARMADUKE GL..87 TASMAN GL..87 MT. CARRINGTON.86 CAROLINE PK..86 CHANCELLOR DOME.85 KEA GL.85 DAINTY GL.85 FOG PK.85 MT McKENZIE.85 JASPUR GL.84 MT. GENDARME.84 MERRIE RA..84 MT. LARKINS.83 PARK PASS GL..83 LLAWRENNY PKS..83 BREWSTER GL..83 JACK GL..83 MT. IRENE.83 VERTEBRAE #12.83 MT. ELLA.82 MT. FRANKLIN.81 DOUGLAS GL.81 BLAIR GL..81 MT. AVOCA.81 MT. GUNN.81 MT. WILSON.78 GLENMARY GL..76 ROLLESTON GL..75 AILSA MTS..75 RIDGE GL..75 BROWNING RA.74 MT. CARIA.74 LANGDALE GL..71 MT FAERIE QUEENE.71 RETREAT GL.71 SNOWY CK.67 KAIKOURA RA.59 New Zealand Glacier Monitoring: End of summer snowline survey

26 5 Discussion 5.1 Ice gain and loss Glaciers accumulate the mass changes of net annual balance variations over years to decades. These effects of yearly climate variations are delayed and distorted before being delivered to the terminus after individual glacier response times have elapsed. The index glaciers records the annual climate related mass gains and losses with some degree of accuracy as the majority of these glaciers are small and steep with relatively fast response times, and have areas that are in equilibrium with the climate of recent decades. The large valley glaciers with long, near 1 year response times have large surface areas inherited in a previous climate, and all are in a state of on-going recession mainly by downwasting of their debris-covered trunks, but recently ice loss has accelerated by the formation of proglacial lakes. For these glaciers, the ELA changes measure only the mass balances of a smaller area that would be in equilibrium with the present climate. Ice mass changes in these glaciers are accounted for in Chinn et al. (212). To assess the mass changes in response to climate fluctuations a cumulative plot of the mass balance indices (MBI) is presented in Figure 5-1. The raw MBI is the inverse of the mean annual departure value and this represents the mean departure from steady state (ELAo). Snowline departure changes with negative ELA (i.e. lower snowline) result in positive MBI. The reliability of use of the ELA as an indicator of mass balance change has been investigated by Chinn et al (25), where the r (correlation) values between the ELA and measured mass balance had an average of.9 with a standard deviation of.7. Mass Balance Index Departure from ELA (m) Cumulative Mass Balance Indices Year Raw MBI Scaled MBI Figure 5-1: Raw and Scaled Cumulative Mass Balance Indices for the index Glaciers. 26 New Zealand Glacier Monitoring: End of summer snowline survey 213

27 The annual trends in the raw MBI as shown in Figure 5-1 agree with the generalised climates given in Table 5-1. However, the cumulative total of the raw MBI on the plot does not agree with the obvious ice volume decrease at most of the index glaciers. Over the course of the 37 year monitoring period, there has been permanent ice loss during large negative mass balance years that has not been recovered after a cycle of positive mass balance years. A negative mass balance year has a greater impact on ice volume than a positive mass balance year for MBIs of the same magnitude. This is due to ablation rates typically being almost twice the accumulation rates on most glaciers. To account for this difference a scaled mass balance index is also shown in Figure 5-1 where negative mass balance years have been scaled by 1.92 and a positive mass balance year departures scaled by 1 (i.e., left unchanged). The scale factors are averages of published mass balance gradient rates (Table 5-2) from studies on the Tasman (Anderton, 1975) and Ivory Glaciers (Anderton and Chinn, 1978) for the period The assumption is that these averaged mass balance gradients apply to the average annual departure values for the index glaciers. The trend in permanent ice area in many of the index glaciers agrees with the cumulative scaled (1.92) mass balance index rather than the cumulative raw mass balance index which does not account for the mass balance gradient. Further work needs to be done to determine what scaling is appropriate for the index glaciers. New Zealand Glacier Monitoring: End of summer snowline survey

28 Table 5-1: Generalised climate for 212/213 year and previous 12 years in Southern Alps and inferred glacier snow input. Glacier year Generalised Climate 1997/1998 Higher frequency of anticyclones and westerly winds over the south, southerlies further north. Temperatures.2 C below normal, but a very warm summer. 1998/1999 Stronger westerly and northwesterly winds over New Zealand, temperatures.8 C above average, with above normal precipitation on the West Coast. 1999/2 Very anticyclonic, with weaker westerlies than normal. Temperatures.7 C above normal, and rainfall slightly below normal. 2/21 More northwesterlies over the South Island, temperatures.2 C above normal. Rainfall close to average. 21/22 Higher than normal pressures and more easterlies over the South Island, temperatures.3 o C above normal, well below average rainfall. 22/23 Persistent westerlies and southwesterlies over New Zealand. Cooler spring, rainfall slightly above average in the west and south. 23/24 More cyclonic westerlies and south westerlies over the South Island from September. 24/25 Cool westerlies during autumn and early winter (temperatures.4 C below normal), then strong cold cyclonic southwesterlies through to December (temperatures.6 C below normal), precipitation overall close to average. 25/26 More anticyclones and mild westerlies and northwesterlies during autumn and winter (winter temperatures.7 C above normal), then more frequent southeasterlies during spring bringing low precipitation. 26/27 More southwesterlies June November bringing increased accumulation, but then anticyclones and south easterlies December March with low precipitation and increased ablation. Temperatures near average overall, and precipitation above average. 27/28 Variable circulation April August with little accumulation. From September on, mainly easterly circulation, and especially warm (1. C above normal) from December with low precipitation and much increased ablation. 28/29 Northerly and easterly quadrant flow anomalies related to La Niña, with associated normal to above normal temperatures, except during Spring. Below normal precipitation during late Winter and Summer. 29/21 Highly variable year with regard to temperature and precipitation swings within and between seasons, particularly for winter 29 and summer 21. More frequent southwesterly flow as a result of El Niño development from spring was opposed to record high temperatures in August 29 and February /211 One of the strongest La Niñas in the last 5 years induced more frequent anticyclones (settled conditions) than normal across New Zealand during summer and autumn. Highs were prominent across the South Island during the ablation season, with warmer than normal temperatures as a whole, elevated sunshine hours, and reduced rainfall. 211/212 Residual La Niña conditions in the Southwest Pacific through winter, with redevelopment of a weak La Niña in spring. More prevalent northerly and easterly quadrant winds on a seasonal scale, except for July-September (more frequent southwesterlies). Month-to-month saw variable circulation patterns that produced both positive and negative temperature anomalies for the Southern Alps, and the warmest May on record. Precipitation was mostly below normal, particularly for the second half of the season, with intermittent snowfall events. 212/213 Neutral ENSO conditions in the southwest Pacific across the glacial year. Anticyclones ( highs ) dominant at the start of the season, and intense ridges of high pressure east of the Chatham Islands extending back over the South Island persisted in the late season. Late spring and early summer characterized by more southwesterly winds. 2 of 3 months in each glacier year season had below normal precipitation, and many sunshine hours and high temperature records were broken. Regional SSTs were near or above normal at the start and end of the year, and near normal at other times. Inferred glacier snow input Average Low Low Average-High Low Average-High Higher High Low Average Very low Low Average Very Low Low Average-Low 28 New Zealand Glacier Monitoring: End of summer snowline survey 213

29 Table 5-2: Vertical gradients of mass balance as measured for Ivory and Tasman Glaciers (mm/m). * is an estimated value. Zone year Ivory Glacier Ablation Ivory Glacier Accumulation Tasman Glacier Ablation Tasman Glacier Accumulation Both Glaciers Ablation Both Glaciers Accumulation Mean * New Zealand Glacier Monitoring: End of summer snowline survey

30 6 Acknowledgements This research was carried out under Contract C1X71 with the Foundation for Research, Science and Technology. Tim Kerr kindly provided Andrew with ARC GIS training and passed on his knowledge in the use of the Photogeoref software for rectifying oblique aerial photographs. Nicolas Fauchereau is thanked for providing reanalysis data on three-monthly circulation patterns. Large parts of the climate text are drawn from the monthly and seasonal climate summaries produced by the National Climate Centre. 7 References Anderton, P.W. (1975) Tasman Glacier Hydrological Research. Annual Report No. 33. Ministry of Works and Development for the National Water and Soil Conservation Organisation, Wellington, New Zealand. 28p Anderton, P.W,; Chinn, T.J.H. (1978) Ivory Glacier, New Zealand, an IHD basin study. Journal of Glaciology, 2(82): Chinn, T.J.H. (1995) Glacier fluctuations in the Southern Alps of New Zealand determined from snowline elevations. Arctic and Alpine Research, 27(2): Chinn, T.J H., Heydenrych, C., Salinger, M.J. (22) New Zealand Glacier Snowline Survey 22. NIWA Client Report, AKL p. National Institute of Water and Atmosphere, Auckland. Chinn, T.J.H., Heydenrych, C., Salinger, M.J. (25) Use of the ELA as a practical method of monitoring glacier response to climate in the New Zealand's Southern Alps. Journal of Glaciology, 51(172): Chinn, T.J.H., Salinger, M.J. (1999) New Zealand Glacier Snowline Survey NIWA Technical Report, p. National Institute of Water and Atmosphere, Wellington. Chinn, T.J.H., Fitzharris, B.B., Willsman, A.P,; Salinger, M.J. (212) Annual ice volume changes for the New Zealand Southern Alps, Global and Planetary Change, 92-93: Chinn, T.J.H., Whitehouse, I.E. (198) Glacier snow line variations in the Southern Alps, New Zealand. pp In: World Glacier Inventory. International Association of Hydrological Sciences, Publication No Clare, G.R,; Fitzharris, B.B., Chinn, T.J.H., Salinger, M.J. (22) Interannual variations in end-of-summer-snowlines of the Southern Alps of New Zealand, and relationships with Southern Hemisphere atmospheric circulation and sea surface temperature patterns. International Journal of Climatology, 22: Corripio J.G. (24) Snow surface albedo estimation using terrestrial photography. International Journal of Remote Sensing, 25(24): New Zealand Glacier Monitoring: End of summer snowline survey 213

31 Gross, G., Kerscher, H., Patzelt, G. (1976) Methodische Untersuchungen über die Schneegrenze in alpinen Gletschergebieten. Zeitschrift für Gletscherkunde und Glazialgeologie, 12: Haeberli, W., Hoezle, M., Zemp, M. (27) Glacier Mass Balance Bulletin, Bulletin No. 9 (24-25) WGMS, 99 p. Staffel Druck Press, Zurich.. Hoelzle, M., Chinn, T.J.H., Stumm, D., Paul, F., Zemp, M., Haeberli, W. (27) The application of inventory data for estimating characteristics of and regional past climate-change effects on mountain glaciers: a comparison between the European Alps and the New Zealand Alps. Global and Planetary Change, 56: Kidson, J.W. (2) An analysis of New Zealand synoptic types and their use in defining weather regimes. International Journal of Climatology, 2: Maisch, M. () Die Gletscher Graubuündens. Geographisches Institut der Universität Zürich. Meier, M.F., Post, A.S. (1962) Recent variations in mass net budgets of glaciers in western North America. pp In: Proceedings of Obergurgl Symposium, International Association of Hydrological Sciences Publication 58. Mullan, A.B. (1998) Southern Hemisphere sea surface temperatures and their contemporary and lag association with New Zealand temperature and precipitation. International Journal of Climatology, 88: Mullan, A.B., Thompson, C.S. (26) Analogue forecasting of New Zealand climate anomalies. International Journal of Climatology, 26: Paterson, W.S.B. (1994) The Physics of Glaciers. Third edition, Oxford, Pergamon Press. 48 p. WGMS (211) Glacier Mass Balance Bulletin No.11 (28-29). Zemp, M., Nussbaumer, S.U., Gartner-Roer, I., Hoelzle, M., Paul, F., and Haeberli, W. (eds.), World Glacier Monitoring Service, Zurich, Switzerland, 12 p. New Zealand Glacier Monitoring: End of summer snowline survey

32 8 Glossary Ablation All processes by which snow and ice are lost from a glacier Accumulation All processes by which snow and ice are added to a glacier. Accumulation Area Ratio (AAR) The ratio of the accumulation area above the equilibrium line, to the entire area of the glacier. Departure of the ELA The elevation difference between the long-term ELAo and the annual snowline altitude. Positive departures mean a higher snowline and therefore a negative mass balance. ELA The mean altitude of the snowline or equilibrium line across a glacier at the end of summer. ELAo The long-term or steady-state altitude of the ELA which will maintain the glacier in equilibrium with the climate. Mass balance index The negative of the ELA departure value. This gives values for annual changes with the same sign as the mass balance changes. Shaded cells Areas which have been measured by digitising. Snowline elevation The snowline elevation is synonymous with ELA when measured at the end of summer. All other snowline elevations apply to a transient seasonal snowline.. Total Area The entire area of the glacier. This may change from year to year, especially on the smaller glaciers. 32 New Zealand Glacier Monitoring: End of summer snowline survey 213

33 Appendix A Index Glacier ELAs (-213) GLACIER GL.IN. No ELAo KAIKOURA RA 621/ M T. ELLA 932B/ M T FAERIE QUEENE 646/ M T. WILSON None M T. FRANKLIN 911A/ ROLLESTON GL. 911A/ M T. CARRINGTON 646C/ M T. AVOCA 685F/ M ARM ADUKE GL. 664C/ RETREAT GL 96A/ BROWNING RA 96A/ DOUGLAS GL 685B/ M T. BUTLER 685C/ DAINTY GL 897/ KEA GL 897/ JASPUR GL 897/ SIEGE GL 893A/ VERTEBRAE #12 893A/ VERTEBRAE #25 893A/ RIDGE GL. 711L/ LANGDALE GL. 711I/ TASM AN GL. 711I/ SALISBURY GL 888B/ JALF GL 886/ CHANCELLOR DOM E 882A/ GLENM ARY GL. 711F/ BLAIR GL. 711D/ M T M ckenzie 711D/ JACKSON GL. 868B/ JACK GL. 875/ M T. ST. M ARY 711B/ THURNEYSON GL 711B/ BREWSTER GL. 868C/ M T. STUART 752I/ LINDSAY GL 867/ FOG PK 752E/ SNOWY CK 752C/ M T. CARIA 863B/ FINDLAY GL. 859/ PARK PASS GL. 752B/ M T. LARKINS 752E/ BRYANT GL. 752B/ AILSA M TS. 752B/ M T. GUNN 851B/ M T. GENDARM E 797G/ LLAWRENNY PKS. 846/ BARRIER PK. 797f/ M T. IRENE 797D/ M ERRIE RA. 797B/ CAROLINE PK. 83/1 138 NUM BER M EAN STD. DEV No. below ELA (+ve balance) % with +ve M.B Shaded columns indicate years of ELA departures below the long term ELAo New Zealand Glacier Monitoring: End of summer snowline survey

34 GLACIER GL.IN. No ELAo KAIKOURA RA 621/ M T. ELLA 932B/ M T FAERIE QUEENE 646/ M T. WILSON None M T. FRANKLIN 911A/ ROLLESTON GL. 911A/ M T. CARRINGTON 646C/ M T. AVOCA 685F/ M ARM ADUKE GL. 664C/ RETREAT GL 96A/ BROWNING RA 96A/ DOUGLAS GL 685B/ M T. BUTLER 685C/ DAINTY GL 897/ KEA GL 897/ JASPUR GL 897/ SIEGE GL 893A/ VERTEBRAE #12 893A/ VERTEBRAE #25 893A/ RIDGE GL. 711L/ LANGDALE GL. 711I/ TASM AN GL. 711I/ SALISBURY GL 888B/ JALF GL 886/ CHANCELLOR DOM E 882A/ GLENM ARY GL. 711F/ BLAIR GL. 711D/ M T M ckenzie 711D/ JACKSON GL. 868B/ JACK GL. 875/ M T. ST. M ARY 711B/ THURNEYSON GL 711B/ BREWSTER GL. 868C/ M T. STUART 752I/ LINDSAY GL 867/ FOG PK 752E/ SNOWY CK 752C/ M T. CARIA 863B/ FINDLAY GL. 859/ PARK PASS GL. 752B/ M T. LARKINS 752E/ BRYANT GL. 752B/ AILSA M TS. 752B/ M T. GUNN 851B/ M T. GENDARM E 797G/ LLAWRENNY PKS. 846/ BARRIER PK. 797f/ M T. IRENE 797D/ M ERRIE RA. 797B/ CAROLINE PK. 83/ NUM BER M EAN STD. DEV No. below ELA (+ve balance) % with +ve M.B New Zealand Glacier Monitoring: End of summer snowline survey 213

35 GLACIER GL.IN. No ELAo KAIKOURA RA 621/ M T. ELLA 932B/ M T FAERIE QUEENE 646/ M T. WILSON None M T. FRANKLIN 911A/ ROLLESTON GL. 911A/ M T. CARRINGTON 646C/ M T. AVOCA 685F/ M ARM ADUKE GL. 664C/ RETREAT GL 96A/ BROWNING RA 96A/ DOUGLAS GL 685B/ M T. BUTLER 685C/ DAINTY GL 897/ KEA GL 897/ JASPUR GL 897/ SIEGE GL 893A/ VERTEBRAE #12 893A/ VERTEBRAE #25 893A/ RIDGE GL. 711L/ LANGDALE GL. 711I/ TASM AN GL. 711I/ SALISBURY GL 888B/ JALF GL 886/ CHANCELLOR DOM E 882A/ GLENM ARY GL. 711F/ BLAIR GL. 711D/ M T M ckenzie 711D/ JACKSON GL. 868B/ JACK GL. 875/ M T. ST. M ARY 711B/ THURNEYSON GL 711B/ BREWSTER GL. 868C/ M T. STUART 752I/ LINDSAY GL 867/ FOG PK 752E/ SNOWY CK 752C/ M T. CARIA 863B/ FINDLAY GL. 859/ PARK PASS GL. 752B/ M T. LARKINS 752E/ BRYANT GL. 752B/ AILSA M TS. 752B/ M T. GUNN 851B/ M T. GENDARM E 797G/ LLAWRENNY PKS. 846/ BARRIER PK. 797f/ M T. IRENE 797D/ M ERRIE RA. 797B/ CAROLINE PK. 83/ NUM BER M EAN STD. DEV No. below ELA (+ve balance) % with +ve M.B New Zealand Glacier Monitoring: End of summer snowline survey

36 Appendix B Index Glacier details 36 New Zealand Glacier Monitoring: End of summer snowline survey 213

37 No. 621/1 KAIKOURA RANGE NZMS 26 sheet O 3 GLACIER DATA Rock Glacier SNOWLINE DATA AREA ha Aspect S Debris area ha ELAo 249 m Max Elev 264 m Max SL 254 m, 1989 Min Elev 22 m Min SL 243 m, 1995 Mean Elev 242 m Mean SL 2491 m Length 1.4 km SL Range 11 m Elev Range 44 m No. surveys 18 Gradient.31 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. DEBRIS TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo no visit 1997 cloud No visit cloud 24 No visit cloud no visit no visit MEAN New Zealand Glacier Monitoring: End of summer snowline survey

38 1 Kaikoura Range Departure from ELA (m) Year Kaikoura Ra. Annual Departures from ELA Kaikoura Range y = *x R2 = Alps annual mean departure from ELA No photograph as this glacier was not visited 38 New Zealand Glacier Monitoring: End of summer snowline survey 213

39 No. 932B/12 Mt ELLA NZMS 26 sheet M3 GLACIER DATA Glacierette SNOWLINE DATA Aspect E AREA 5.32 ha ELAo 2142 m Max Elev 225 m Max SL >225 m, 211 Min Elev 28 m Min SL 2 m, 1995 Mean Elev 2165 m Mean SL 2139 m Length.34 km SL Range 25 m Elev Range 17 m No. surveys 2 Gradient.5 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo In cloud No visit cloud > MEAN New Zealand Glacier Monitoring: End of summer snowline survey

40 2 Mt Ella 15 Departure from ELA (m) Year 2 Mt Ella correlation y = *x R2 = Mt Ella Annual Departures from ELA Alps annual mean departure from ELA No photograph as this glacier was not visited 4 New Zealand Glacier Monitoring: End of summer snowline survey 213

41 No. 646/6 FAERIE QUEENE NZMS 26 sheet M 31 GLACIER DATA Glacierette SNOWLINE DATA Aspect SE AREA 5.74 ha ELAo 23 m Max Elev 22 m Max SL >22 m, 211 Min Elev 194 m Min SL 192 m, 1995 Mean Elev 27 m Mean SL m Length.36 km SL Range 28 m Elev Range 26 m No. Surveys 21 Gradient.72 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELA no visit cloud > MEAN New Zealand Glacier Monitoring: End of summer snowline survey

42 2 Faerie Queene 15 Departure from ELA (m) Year 25 Faerie Queene Correlation y = *x R2 =.71 Faerie Queen Annual Departures from ELA Alps annual mean departure from ELA No photograph as this glacier was not visited 42 New Zealand Glacier Monitoring: End of summer snowline survey 213

43 Not numbered Mt WILSON NZMS 26 sheet K33 Snow patch GLACIER DATA SNOWLINE DATA Aspect S AREA to.68 ha ELAo 7.3 ha Max Elev 23 m Max SL 225 m, 1999 Min Elev 174 m Min SL 1745 m, 1993 Mean Elev 1885 m Mean SL 195 m Length N/A SL Range 28 m Elev Range 29 m No. Surveys 3 Gradient MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha N/A ha (AAR) INDEX ELA N/A 7.3 N/A Mean New Zealand Glacier Monitoring: End of summer snowline survey

44 2 Mt Wilson 15 Departure from ELA (m) Year 2 Mt Wilson correlation y = *x R2 =.78 Mt Wilson Annual Departures from ELA Alps annual mean departure from ELA Photograph 4: Mt Wilson 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

45 No. 911A/2 Mt. FRANKLIN NZMS 26 sheet K33 Cirque GLACIER DATA SNOWLINE DATA Aspect E AREA 8.85 ha ELAo 1814 m Max Elev 21 m Max SL 198 m, 211 Min Elev 168 m Min SL 165 m, 1993 Mean Elev 1845 m Mean SL 1825 m Length.5 km SL Range 33 m Elev Range 33 m No. Surveys 28 Gradient.66 MEASUREMENTS YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo ? cloud cloud Mean New Zealand Glacier Monitoring: End of summer snowline survey

46 2 Mt Franklin 15 Departure from ELA (m) Year 2 Mt Franklin correlation y = *x R2 =.81 Mt Franklin Annual Departures from ELA Alps annual mean departure from ELA Photograph 5: Mt Franklin 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

47 No. 911A /4 ROLLESTON GL. NZMS 26 sheet K33 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA 1.8 ha ELAo 1763 m Max Elev 19 m Max SL 1868 m, 1993, 95 Min Elev 171 m Min SL 162 m, 2 Mean Elev 185 m Mean SL 1763 m Length.36 km SL Range 248 m Elev Range 19 m No. Surveys 34 Gradient.53 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

48 2 Rolleston Gl. 15 Departure from ELA (m) Year 2 Rolleston correlation y = *x R2 =.75 Rolleston Annual Departures from ELA Alps annual mean departure from ELA Photograph 6: Rolleston Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

49 No. 664C/21 Mt CARRINGTON NZMS sheet K33 Cirque glacier GLACIER DATA SL DATA Aspect S AREA 15.5 ha ELAo 1715 m Max Elev 196 m Max SL 196 m, 211 Min Elev 1595 m Min SL 1545 m, 1993 Mean Elev 1778 m Mean SL 175 m Length.71 km SL Range 415 m Elev Range 365 m No. Surveys 31 Gradient.51 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

50 25 Mt Carrington 2 Departure from ELA (m) Year 3 Carrington correlation y = *x R2 = Carrington Annual Departures from ELA Alps annual mean departure from ELA Photograph 7: Carrington 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

51 No. 685F/4 Mt AVOCA NZMS sheet K34 Glacierette GLACIER DATA SNOWLINE DATA Aspect E AREA 9.83 m ELAo 1965 m Max Elev 28 m Max SL 28 m, 1999 Min Elev 189 m Min SL 185 m, 1993 Mean Elev 1985 m Mean SL 1965 m Length.36 km SL Range 23 m Elev Range 19 m No. Surveys 28 Gradient.53 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELA MEAN New Zealand Glacier Monitoring: End of summer snowline survey

52 2 Mt Avoca 15 Departure from ELA (m) Year 2 Mt Avoca correlation y = *x R2 =.81 Mt Avoca Annual Departures from ELA Alps annual mean departure from ELA Photograph 8: Mt Avoca 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

53 No. 664C/12 MARMADUKE DIXON GL NZMS 26 sheet K33 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect E AREA 93 m ELAo 183 m Max Elev 21 m Max SL 1998 m, 199 Min Elev 1615 m Min SL 1655 m, 1993 Mean Elev 1858 m Mean SL 1839 m Length 1.7 km SL Range 343 m Elev Range 485 m No. Surveys 35 Gradient.285 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

54 2 Marmaduke Dixon Gl Departure from ELA (m) Year 3 Marmaduke correlation y = *x R2 =.87 Marmaduke Annual Departures from ELA Alps annual mean departure from ELA Photograph 9: Marmaduke Dixon 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

55 No. 96A/4 RETREAT GL. NZMS 26 sheet K33 Moutain glacier GLACIER DATA SNOWLINE DATA Aspect SW AREA 28.7 ha ELAo 1742 m Max Elev 193 m Max SL 1888 m, 1999 Min Elev 157 m Min SL 1465 m, 1995 Mean Elev 175 m Mean SL 173 m Length 1.5 km SL Range 423 m Elev Range 36 m No. Surveys 29 Gradient.343 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo > MEAN New Zealand Glacier Monitoring: End of summer snowline survey

56 2 Retreat Gl. 15 Departure from ELA (m) Year 2 Retreat correlation y = *x R2 =.71 Retreat Annual Departures from ELA Alps annual mean departure from ELA Photograph 1: Retreat Glacier on 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

57 96A/1 BROWNING RA. NZMS 26 sheet J33 Small cirque GLACIER DATA SNOWLINE DATA Aspect S AREA 4.8 ha ELAo 1598 m Max Elev 17 m Max SL >179 m, 2 Min Elev 153 m Min SL 148 m, 1995 Mean Elev 1615 m Mean SL 1576 m Length km SL Range 22 m Elev Range 17 m No. Surveys 29 Gradient MEASUREMENTS Digitised values in bold type YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo >>179 above gl >>179 above gl > MEAN New Zealand Glacier Monitoring: End of summer snowline survey

58 2 Browning Range 15 Departure from ELA (m) Year 2 Browning correlation y = *x R2 =.74 Browning Annual Departures from ELA Alps annual mean departure from ELA Photograph 11: Browning Range 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

59 No. 685B/1 DOUGLAS GL NZMS 26 sheet J35 Small mountain glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA ha ELAo 24 m Max Elev 244 m Max SL 238 m, 28 Min Elev 182 m Min SL 178 m,1993 Mean Elev 213 m Mean SL 25 m Length 1.18 km SL Range 6 m Elev Range 62 m No. Surveys 31 Gradient.58 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo Mean New Zealand Glacier Monitoring: End of summer snowline survey

60 Departure from ELA (m) Douglas Gl Year 3 Douglas correlation y = *x R2 = Douglas Annual Departures from ELA Alps annual mean departure from ELA Photograph 12: Douglas Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

61 No. 685C/6 Mt BUTLER NZMZ 26 sheet J34 Shelf glacier GLACIER DATA SL DATA Aspect E AREA 75 ha ELAo 184 m Max Elev 24 m Max SL 255 Min Elev 168 m Min SL 164 m, 1995 Mean Elev 186 m Mean SL 1827 m Length 1 km SL Range 415 m Elev Range 36 m No. surveys 35 Gradient MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo Mean New Zealand Glacier Monitoring: End of summer snowline survey

62 2 Mt Butler 15 Departure from ELA (m) Year 2 Butler correlation y = *x R2 = Butler Annual Departures from ELA Alps annual mean departure from ELA Photograph 13: Mt Butler 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

63 No DAINTY GL. NZMS sheet J34 Mountain gl, reliability A GL DATA SL DATA Aspect W AREA ha ELA 1954 m Max Elev 233 m Max SL 217 m, 211 Min Elev 175 m Min SL 1778 m, 1993 Mean Elev 24 m Mean SL 1944 m Length 1.45 km SL Range 392 m Elev Range 58 m No. Surveys 33 Gradient.4 MEASUREMENTS Digitised values in bold type YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELA ACCUM. ABL. TOTAL AREA RATIBALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

64 25 Dainty Gl. 2 Departure from ELA (m) Year 25 Dainty correlation y = *x R2 =.85 2 Dainty Annual Departures from ELA Alps annual mean departure from ELA Photograph 14: Dainty Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

65 No. 897/7 KEA GL NZMS 26 sheet J34 Cirque GL DATA SL DATA Aspect S AREA ha ELAo 182 m Max Elev 23 m Max SL 22 m, 1999 Min Elev 165 m Min SL 157 m, 1995 Mean Elev 184 m Mean SL 1799 m Length.95 km SL RANGE 45 m Elev Range 38 m No. Surveys 31 Gradient.453 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAoACCUM. ABL. TOTAL AREA RATIBALANCE m m ha ha ha (AAR) INDEX ELAo no flight > MEAN New Zealand Glacier Monitoring: End of summer snowline survey

66 Departure from ELA (m) Kea Gl Year 3 Kea correlation y = *x R2 = Kea Annual Departures from ELA Alps annual mean departure from ELA Photograph 15: Kea Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

67 No. 897/1 to 5 JASPUR GL. NZMS sheet I34 Glacierette group GLACIER DATA SNOWLINE DATA Aspect SW AREA 14.9 ha ELAo 1725 m Max Elev 192 m Max SL >195 m, 211 Min Elev 16 m Min SL 157 m, 1983 Mean Elev 176 m Mean SL 1674 m Length km SL Range 35 m Elev Range 32 m No. Surveys 29 Gradient MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo no flight no flight no flight > > > > MEANS New Zealand Glacier Monitoring: End of summer snowline survey

68 2 Jaspur Gl. 15 Departure from ELA (m) Year 25 Jaspur correlation y = *x R2 =.84 2 Jaspur Annual Departures from ELA Alps annual mean departure from ELA Photograph 16: Jaspur Group 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

69 No. 893A-6 SIEGE GL. NZMS 26 sheet I35 Valley glacier GLACIER DATA SNOW LINE DATA Aspect SE AREA ha ELAo 1736 m Max Elev 213 m Max SL 218 m, 211 Min Elev 137 m Min SL 134 m, 1995 Mean Elev 175 m Mean SL 1675 m Length km SL Range 81 m Elev Range 76 m No. Surveys 32 Gradient.239 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo no flight no flight no flight MEANS New Zealand Glacier Monitoring: End of summer snowline survey

70 Departure from ELA (m) Siege Gl Year Siege correlation 6 y = *x R2 =.9 5 Siege Annual Departures from ELA Alps annual mean departure from ELA Photograph 17: Seige Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

71 893A-12 VERTEBRAE COL No 12 NZMS 26 sheet I35 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect SW AREA 2.64 ha ELAo 1864 m Max Elev 21 m Max SL 29 m, 1999 Min Elev 173 m Min SL 1768 m, Mean Elev 1915 m Mean SL 1866 m Length.63 km SL Range 322 m Elev Range 37 m No. surveys 31 Gradient.592 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo no flight no visit no flight no flight MEAN New Zealand Glacier Monitoring: End of summer snowline survey

72 25 Vertebrae #12 Gl Departure from ELA (m) Year 3 Vertebrae 12 correlation y = *x R2 =.83 Verterbrae 12 Annual Departures from ELA Alps annual mean departure from ELA Photograph 18: Vertebrae Glacier 12 (partially obscured on the left) 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

73 893A/ 25 VERTEBRAE COL No. 25 NZMS 26 sheet I35 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect SW Area ha ELAo 184 m Max Elev 24 m Max SL 1995 m, 1999 Min Elev 17 m Min SL 1746 m, Mean Elev 185 m Mean SL 1835 m Length 1.15 Km km SL Range 249 m Elev Range 36 m m No. surveys 31 Gradient.313 No 25 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

74 2 Vertebrae #25 Gl. 15 Departure from ELA (m) Year 2 Vertebrae 25 correlation y = *x R2 =.91 Vertebrae 25 Annual Departures from ELA Alps annual mean departure from ELA Photograph 19: Vertebrae Glacier 25 (clear of cloud in the centre) 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

75 711L-24 RIDGE GL. NZMS sheet L24 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA 68. ha ELAo 2226 m Max Elev 249 m Max SL >249 m,211 Min Elev 211 m Min SL 285 m, Mean Elev 23 m Mean SL 2226 m Length 1.4 km SL Range 45 m Elev Range 38 m No. surveys 3 Gradient.365 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo no flight no flight no flight > MEAN New Zealand Glacier Monitoring: End of summer snowline survey

76 2 Ridge Gl. 15 Departure from ELA (m) Year 2 Ridge correlation y = *x R2 = Ridge Annual Departures from ELA Alps annual mean departure from ELA Photograph 2: Ridge Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

77 No. 711 I/35 LANGDALE GL. NZMS 26 sheet H36 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect NW AREA 34.1 ha ELA 2186 m Max Elev 258 m Max SL >258 m,211 Min Elev 29 m Min SL 1955 m, Mean Elev 2335 m Mean SL 2185 m Length 1.3 km SL Range 625 m Elev Range 49 m No. surveys 33 Gradient.478 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELA ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo no flight no flight no flight > MEAN New Zealand Glacier Monitoring: End of summer snowline survey

78 Departure from ELA (m) Langdale Gl Year 3 Langdale correlation y = *x R2 = Langdale Annual Departures from ELA Alps annual mean departure from ELA Photograph 21: Langdale Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

79 No. 711I/12 TASMAN GL. NZMS 26 sheet Valley glacier GLACIER DATA SNOWLINE DATA Aspect SW Max Elev ELAo to '1 Min Elev ELA 187 to '1 Mean Elev Max SL 211 m, 211 Elev Range Min SL 1666 m, 1995 Length Mean SL 187 m Gradient SL Range 444 m S.96 No. surveys 37 MEASUREMENTS Values from contour counts shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELA ACCUM. ABL. TOTAL AREA RATIOBALANCE m m ha ha ha (AAR) INDEX ELAo 179 Too large to measure MEAN New Zealand Glacier Monitoring: End of summer snowline survey

80 Departure from ELA (m) Tasman Gl Year 4 Tasman correlation y = *x R2 = Tasman Annual Departures from ELA Alps annual mean departure from ELA Photograph 22: Tasman Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

81 No. 888B/3 SALISBURY SNOWIELD NZMS 26 sheet H35 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect SW AREA ha ELAo 181 m Max Elev 239 m Max SL 295 m, 1999 Min Elev 134 m Min SL 1645 m, 1995 Mean Elev 1865 m Mean SL 187 m Length 2.98 km SL Range 45 m Elev Range 15 m No. surveys 34 Gradient.352 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo No flight No flight No flight Mean New Zealand Glacier Monitoring: End of summer snowline survey

82 3 Salisbury Gl. 25 Departure from ELA (m) Year 3 Salisbury correlation y = *x R2 = Salisbury Annual Departures from ELA Alps annual mean departure from ELA Photograph 23: Salisbury Snowfield 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

83 No. 886/2 & 888B/7 JALF GL. and Baumann Gl. NZMS 26 sheet H35 Small saddle glacier GLACIER DATA (28) SNOWLINE DATA Aspects N &S, E & W AREA 41.5 ha ELAo 179 m Max Elev 188 m Max SL 216 m, 2 Min Elev 16 m Min SL 155 m, 1995 Mean Elev 174 m Mean SL 177 m Length na SL Range 61 m Elev Range 28 m No. surveys 33 Gradient na Glacier area has reduced since the first map in MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo no visit no visit no visit MEAN New Zealand Glacier Monitoring: End of summer snowline survey

84 3 25 Jalf Gl Departure from ELA (m) Year Jalf correlation 4 y = *x R2 = Jalf Annual Departures from ELA Alps annual mean departure from ELA Photograph 24: Jalf Glacier (obscured under cloud on left) 12 March 213. Snowline elevation determined from the Fritz Range glaciers in this photo. 84 New Zealand Glacier Monitoring: End of summer snowline survey 213

85 No. 882A/7 CHANCELLOR DOME NZMS 26 sheet H35 & H36 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect SW AREA ha ELAo 1756 m Max Elev 196 m Max SL 2 m, 211 Min Elev 166 m Min SL 1545 m, 1995 Mean Elev 181 m Mean SL 1739 m Length.55 km SL Range 455 m Elev Range 3 m No. surveys 32 Gradient.436 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

86 25 Chancellor Dome Departure from ELA (m) Year 25 Chancellor correlation y = *x R2 =.85 Chancellor Annual Departures from ELA Alps annual mean departure from ELA Photograph 25: Chancellor Glacier 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

87 No. 711F/6 GLENMARY GL. NZMS 26 sheet H37 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect S AREA ha ELAo 2164 m Max Elev 238 m Max SL 235 m, 211 Min Elev 24 m Min SL 22 m, Mean Elev 221 m Mean SL 2168 m Length 1.19 km SL Range 285 m Elev Range 34 m No. Surveys 31 Gradient.277 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo Mean New Zealand Glacier Monitoring: End of summer snowline survey

88 2 Glenmary Gl. 15 Departure from ELA (m) Year 2 Glenmary correlation y = *x R 2 =.76 Glenmary Annual Departures from ELA Alps annual mean departure from ELA Photograph 26: Glenmary Glacier on 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

89 No. 711-D/38 BLAIR GL. NZMS 26 sheet H37 & G37 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA ha ELAo 1938 m Max Elev 224 m Max SL 216 m, 211 Min Elev 179 m Min SL 1812 m, 1983 Mean Elev 215 m Mean SL 1939 m Length.63 km SL Range 348 m Elev Range 45 m No. Surveys 3 Gradient.71 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

90 25 Blair Gl. 2 Departure from ELA (m) Year 25 Blair correlation y = *x R 2 =.81 2 Blair Annual Departures from ELA Alps annual mean departure from ELA Photograph 27: Blair Glacier on 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

91 No. 711D/21 Mt. McKENZIE NZMS 26 sheet G37 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect S AREA ha ELAo 194 m Max Elev 21 m Max SL 285 m, 211 Min Elev 176 m Min SL 1715 m, 1983 Mean Elev 193 m Mean SL 189 m Length.69 km SL Range 37 m Elev Range 34 m No. Surveys 31 Gradient.49 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

92 2 Mt McKenzie 15 Departure from ELA (m) Year 2 McKenzie correlation y = *x R 2 =.85 McKenzie Annual Departures from ELA Alps annual mean departure from ELA Photograph 28: McKenzie Glacier on 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

93 No. 868B/94 JACKSON GL NZMS 26 sheet H37 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect NW AREA ha ELAo 27 m Max Elev 23 m Max SL 223 m, 211 Min Elev 192 m Min SL 199 m, Mean Elev 211 m Mean SL 268 m Length.5 km SL Range 24 m Elev Range 38 m No. Surveys 29 Gradient.76 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey

94 2 Jackson Gl. 15 Departure from ELA (m) Year 2 Jackson correlation y = *x R 2 =.89 Jackson Annual Departures from ELA Alps annual mean departure from ELA Photograph 29: Jackson Glacier on 12 March New Zealand Glacier Monitoring: End of summer snowline survey 213

95 3 Jack Gl. 25 Departure from ELA (m) Year 3 Jack correlation y = *x R 2 = Jack Annual Departures from ELA Alps annual mean departure from ELA Photograph 3: Jack Glacier under cloud (on the left) on 12 March 213. Snowline elevation determined from the Hooker Glacier in this photo. New Zealand Glacier Monitoring: End of summer snowline survey

96 No. 711B/39 Mt. St. MARY NZMS 26 sheet G38 Rock glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA ha ELAo 1926 m Max Elev 22 m Max SL 218 m, 211 Min Elev 176 m Min SL 1755 m, Mean Elev 198 m Mean SL 1919 m Length.7 km SL Range 425 m Elev Range 44 m No. Surveys 26 Gradient.629 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

97 3 Mt St Mary 25 Departure from ELA (m) Year 3 Mt St. Mary correlation y = *x R 2 =.88 Mt St. Mary Annual Departures from ELA Alps annual mean departure from ELA Photograph 31: Mt St Mary on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

98 No. 711B/12 THURNEYSTON GL. NZMS 26 sheet G38 Mountain gl, reliability C GLACIER DATA SNOWLINE DATA Aspect S AREA ha ELA 197 m Max Elev 245 m Max SL 215 m, 2 Min Elev 172 m Min SL 1865 m, 1983 Mean Elev 285 m Mean SL 1966 m Length 1.23 km SL Range 285 m Elev Range 73 m No. Surveys 32 Gradient.59 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELA ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

99 2 Thurneyson Gl. 15 Departure from ELA (m) Year 2 Thurneyson correlation y = *x R 2 =.9 Thurneyson Annual Departures from ELA Alps annual mean departure from ELA Photograph 32: Thurneyson Glacier on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

100 No. 868C-2 BREWSTER GL. NZMS 26 sheet G38 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect S AREA ha ELAo 1935 m Max Elev 239 m Max SL 2285 m, 211 Min Elev 1655 m Min SL 175 m, 1993 Mean Elev 223 m Mean SL 1921 m Length 2.69 km SL Range 535 m Elev Range 735 m No. Surveys 32 Gradient.27 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

101 Departure from ELA (m) Brewster Gl Year 4 Brewster correlation y = *x R 2 = Brewster Annual Departures from ELA Alps annual mean departure from ELA Photograph 33: Brewster Glacier on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

102 No. 752 I-14 Mt. STUART NZMS 26 sheet G38 Moutain glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA ha ELAo 1673 m Max Elev 186 m Max SL 1858 m, 211 Min Elev 157 m Min SL 1515 m, 1995 Mean Elev 1715 m Mean SL 1668 m Length.54 km SL Range 343 m Elev Range 29 m No. Surveys 31 Gradient.54 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. Glacier Ice Area AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

103 2 Mt Stuart 15 Departure from ELA (m) Year 2 Stuart correlation y = *x R 2 = Stuart Annual Departures from ELA Alps annual mean departure from ELA Photograph 34: Stuart Glacier on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

104 No. 867/2 LINDSAY GL. NZMS 26 sheet F37 Mountain shelf glacier GLACIER DATA SNOWLINE DATA Aspect S AREA ha ELAo 173 m Max Elev 188 m Max SL 1878 m, 211 Min Elev 161 m Min SL 155 m, 1995 Mean Elev 1745 m Mean SL 1718 m Length.57 km SL Range 328 m Elev Range 27 m No. Surveys 31 Gradient.47 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

105 2 Lindsay Gl. 15 Departure from ELA (m) Year 2 Lindsay correlation y = *x R 2 =.87 Lindsay Annual Departures from ELA Alps annual mean departure from ELA Photograph 35: Lindsay Glacier on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

106 No. 752 E/51 FOG PK. NZMS 26 sheet F39 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA ha ELAo 1987 m Max Elev 215 m Max SL 2135 m, Min Elev 184 m Min SL 1888 m, 1995 Mean Elev 1995 m Mean SL 1995 m Length.4 km SL Range 247 m Elev Range 31 m No. Surveys 28 Gradient.775 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo > > > > > > > > > > > MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

107 Fog Pk Departure from ELA (m) Year 2 Fog correlation y = *x R 2 = Fog Annual Departures from ELA Alps annual mean departure from ELA Photograph 36: Fog Peak on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

108 No. 752C/13 SNOWY CK NZMS 26 sheet E4 Small mountain glacier GLACIER DATA SNOWLINE DATA Aspect W AREA ha ELAo 292 m Max Elev 221 m Max SL >224 m, 211 Min Elev 2 m Min SL 24 m, 1997 Mean Elev 215 m Mean SL 283 m Length.73 km SL Range 26 m Elev Range 21 m No. Surveys 32 Gradient.29 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo > MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

109 2 Snowy Pk. 15 Departure from ELA (m) Year Snowy correlation y = *x R 2 = Snowy Annual Departures from ELA Alps annual mean departure from ELA Photograph 37: Snowy Peak on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

110 No. 863B/1 Mt. CARIA NZMS 26 sheet E39 Small cirque GLACIER DATA SNOWLINE DATA Aspect SE AREA ha ELAo 1472 m Max Elev 16 m Max SL >166 m, 211 Min Elev 14 m Min SL 1366 m, 1995 Mean Elev 15 m Mean SL 1455 m Length.3 km SL Range 234 m Elev Range 2 m No. Surveys 3 Gradient.67 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo > MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

111 2 Mt Caria 15 Departure from ELA (m) Year Mt Caria correlation y = *x R 2 =.74 2 Mt Caria Annual Departures from ELA Alps annual mean departure from ELA Photograph 38: Mt Caria on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

112 No. 859/9 FINDLAY GL. NZMS 26 sheet E39 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect SW AREA ha ELAo 1693 m Max Elev 19 m Max SL 189 m, 1999 Min Elev 155 m Min SL 1561 m, 1995 Mean Elev 1725 m Mean SL 1686 m Length.875 km SL Range 329 m Elev Range 35 m No. Surve 28 Gradient.4 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo Mean New Zealand Glacier Monitoring: End of summer snowline survey 213

113 Findlay Gl Departure from ELA (m) Year 25 Findlay correlation y = *x R 2 =.91 2 Findlay Annual Departures from ELA Alps annual mean departure from ELA No photograph as this glacier was not visited New Zealand Glacier Monitoring: End of summer snowline survey

114 No. 752 B/48 PARK PASS GL. NZMS 26 sheet E 4 Valley glacier GLACIER DATA SNOWLINE DATA Aspect S AREA ha ELAo 1824 m Max Elev 22 m Max SL 25 m, 211 Min Elev 15 m Min SL 1635 m, 1995 Mean Elev 185 m Mean SL 1824 m Length 2.63 km SL Range 37 m Elev Range 7 m No. Surveys 3 Gradient.267 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo Mean New Zealand Glacier Monitoring: End of summer snowline survey 213

115 2 Park Pass Gl Departure from ELA (m) Year 2 Park Pass correlation y = *x R 2 =.83 Park Pass Annual Departures from ELA Alps annual mean departure from ELA Photograph 4: Park Pass Glacier on 12 March 213. Lower terminus covered by cloud (left hand side of photo). New Zealand Glacier Monitoring: End of summer snowline survey

116 No. 752 E/2 MT. LARKINS NZMS sheet E 41 Glacierette GLACIER DATA SNOWLINE DATA Aspect SE AREA ha ELAo 1945 m Max Elev 222 m Max. SL 2215 m, Min Elev 168 m Min. SL 163 m, 1995 Mean Elev 195 m Mean SL 1951 m Length.5 km SL Range 585 m Elev Range 54 m No. surveys 26 Gradient 1.8 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

117 Departure from ELA (m) Mt Larkins Year 3 Larkins correlation y = *x R 2 = Larkins Annual Departures from ELA Alps annual mean departure from ELA Photograph 43: Mt Larkins on 28 April 213. Taken from the ground at the site of the climate station. New Zealand Glacier Monitoring: End of summer snowline survey

118 No. 752B/25 BRYANT GL. NZMS sheet E41 Mountain glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA 29.7 ha ELAo 1783 m Max Elev 218 m Max. SL 29 m, 211 Min Elev 166 m Min. SL 161 m, 1995 Mean Elev 192 m Mean SL 177 m Length.94 km SL Range 48 m Elev Range 52 m No. surveys 31 Gradient.55 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

119 3 Bryant Gl. 25 Departure from ELA (m) Year 3 Bryant correlation y = *x R 2 =.89 Bryant Annual Departures from ELA Alps annual mean departure from ELA Photograph 45: Bryant Glacier on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

120 No. 752B-13 AILSA MTS NZMS 26 sheet D4 Cirque glacier GL DATA SNOWLINE DATA Aspect S AREA ha ELAo 1648 m Max Elev 183 m Max SL 183 m, 1999 Min Elev 153 m Min SL 1555 m, 1995 Mean Elev 168 m Mean SL 1631 m Length.75 km SL Range 275 m Elev Range 3 m No. surveys 28 Gradient.4 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

121 2 Ailsa Mts 15 Departure from ELA (m) Year 2 Ailsa correlation y = *x R 2 = Ailsa Annual Departures from ELA Alps annual mean departure from ELA Photograph 47: Ailsa Glacier on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

122 No. 851B/57 Mt. GUNN NZMS 26 sheet D4 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect SE AREA ha ELAo 1593 m Max Elev 186 m Max SL 182 m, 211 Min Elev 147 m Min SL 1471 m, 1995 Mean Elev 1665 m Mean SL 1587 m Length.75 km SL Range 349 m Elev Range 39 m No. surveys 3 Gradient.52 MEASUREMENTS Digitised values shaded YEAR SNOWLINEDEPARTURE AREAS ACCUM. MASS ELEVATIONFROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

123 25 Mt Gunn 2 Departure from ELA (m) Year 3 Gunn correlation y = *x R 2 = Gunn Annual Departures from ELA Alps annual mean departure from ELA Photograph 48: Mt Gunn on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

124 No. 797G/33 Mt. GENDARME NZMS sheet D4 & 41 Mountain gl, reiability B GLACIER DATA SNOWLINE DATA Aspect S Area ha ELA 1616 m Max Elev 19 m Max SL 184 m, 1999 Min Elev 144 m Min SL 1418 m, 1995 Mean Elev 167 m Mean SL 1589 m Length.525 km SL range 386 m Elev Range 46 m No. surveys 28 Gradient.88 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELA ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

125 2 Gendarme 15 Departure from ELA (m) Year 2 Gendarme correlation y = *x R 2 =.84 Gendarme Annual Departures from ELA Alps annual mean departure from ELA Photograph 5: Mt Genderme on 12 March 213. New Zealand Glacier Monitoring: End of summer snowline survey

126 No. 846/35 LlAWRENNY PKS. NZMS 26 sheet D4 Cirque glacier GLACIER DATA SNOWLINE DATA Aspect SW AREA 18.6 ha ELAo 1476 m Max Elev 168 m Max SL 167 m, 1999 Min Elev 131 m Min SL 13 m, 1995 Mean Elev 1495 m Mean SL 1458 m Length.75 km SL Range 37 m Elev Range 37 m No. surveys 28 Gradient.49 MEASUREMENTS Digitised values shaded YEAR SNOWLINE DEPARTURE AREAS ACCUM. MASS ELEVATION FROM ELAo ACCUM. ABL. TOTAL AREA RATIO BALANCE m m ha ha ha (AAR) INDEX ELAo MEAN New Zealand Glacier Monitoring: End of summer snowline survey 213

127 2 Llawrenny Peaks 15 Departure from ELA (m) Year 2 Llawrenny correlation y = *x R 2 =.83 Llawrenny Annual Departures from ELA Alps annual mean departure from ELA Photograph 51: Llawrenny Peaks on 12 March 213. Upper parts of this glacier are visible on the left side of the photograph. New Zealand Glacier Monitoring: End of summer snowline survey